Optical fiber tap utilizing reflector

Abstract

A tap for withdrawing light from an intermediate portion of an optical fiber core by passing light through a side of the optical fiber comprises an optical coupler in contact with an outside surface of an optical fiber which is bent and disposed in a plane. A light reflector (41) extending transverse to the plane deflects the withdrawn light (3) towards the end surface (5) of a light element (6) disposed completely outside the plane. A similar arrangement may be used to inject light to an intermediate portion of an optical fiber. The tap may be used as a read tap to withdraw light, or as a write tap to inject light in optical fiber networks.

What is claimed is: 
     
       1. A tap for withdrawing light from an intermediate portion of an optical fiber core by passing the light through a side of the optical fiber, comprising: a light element having an end surface;   means for maintaining the intermediate portion of the optical fiber bent and disposed in a plane, the end surface of the light element being completely outside the plane;   an optical coupler in contact with an outer surface of the optical fiber;   a light reflector extending traverse to the plane so as to deflect the withdrawn light toward the light element end surface.   
     
     
       2. The tap of claim 1, the light reflector having a reflecting surface thereon with a reflectance greater than 0.50 and extending in a position so as to reflect at least 20% of the withdrawn light. 
     
     
       3. The tap of claim 1, the maintaining means being releasable so that the optical fiber can be completely removed therefrom when so released. 
     
     
       4. The tap of claim 1, the light reflector being non-planar and curved in at least one dimension so as to focus the withdrawn light onto the end surface of the light element. 
     
     
       5. The tap of claim 1, the reflectance being greater than 0.95. 
     
     
       6. The tap of claim 1, further comprising the intermediate portion of the optical fiber which includes a core, a cladding, and a polymeric coating, the withdrawn light passing through the coating, the bent optical fiber portion being disposed in a substantially flat plane, the optical coupler contacting the bent optical fiber portion. 
     
     
       7. The tap of claim 1, the bent optical fiber portion defining a macrobend having a bend amplitude greater than twice a diameter of a cladding of the fiber. 
     
     
       8. The tap of claim 7, the bent optical fiber portion defining a series of microbends having bend amplitudes less than twice a diameter of a cladding of the fiber. 
     
     
       9. The tap of claim 1, the bent optical fiber portion defining a series of microbends having bend amplitudes less than twice a diameter of a cladding of the fiber. 
     
     
       10. The tap of claim 1, the light reflector being a deflection surface located a distance less than 4 mm from a furthermost upstream section of the bent optical fiber portion. 
     
     
       11. The tap of claim 10, the light reflector having a reflective coating disposed thereon. 
     
     
       12. The tap of claim 1, the maintaining means including a light waveguide extending from the bent optical fiber portion to the light reflector. 
     
     
       13. The tap of claim 1, the maintaining means including a substrate having a curved groove formed therein sized to accept an optical fiber coating and to maintain the optical fiber portion bent in a substantially constant attitude, the light reflector being formed in the substrate adjacent an outer portion of the groove, and also including a resilient force means for urging the optical fiber portion within the groove. 
     
     
       14. The tap of claim 1, the light element including a pigtail waveguide having an end which forms the light element end surface. 
     
     
       15. The tap of claim 1, the light element end surface being located beneath the plane and under the deflection surface and within 4 mm of a furthermost section of the bent optical fiber portion. 
     
     
       16. A tap for injecting light into an intermediate portion of an optical fiber core by passing the light through a side of the optical fiber, comprising: a light source having an end surface;   means for maintaining the intermediate portion of the optical fiber bent and disposed in a plane, the end surface of the light element being completely outside the plane;   an optical coupler in contact with an outer surface of the optical fiber;   a light reflector extending traverse to the plane so as to deflect at least 20% of the light from the light source end surface toward the optical fiber bent portion, a reflectance of the light reflector being greater than 0.50.   
     
     
       17. A method of making a tap for coupling light between a light element and an intermediate portion of an optical fiber by passing the light through a side of an optical fiber polymeric coating, comprising the steps of: molding a substrate so as to include means for maintaining the intermediate portion of the optical fiber bent and disposed in a flat first plane, the substrate being molded so as to form a light reflector for deflecting light between the first plane and a second plane non-parallel to the first plane so as to form a continuous light path between the bent optical fiber portion and an end surface of a light element disposed outside the first plane, the light reflector being formed so as to have a reflectance in excess of 0.80.